As to a process for producing olefin oxides, olefin epoxidation in the presence of a metal-based catalyst has been proposed. For example, US2003/0191328 mentions a process for the epoxidation of hydrocarbon with oxygen in the presence of a mixture containing at least two metals from the specific metal group on a support having a specific BET surface area.
JP2002-371074 mentions a process for producing an oxirane compound which process uses a metal oxide catalyst containing at least one metal selected from the metals belonging to the Groups III to XVI of the periodic table.